It seems that NASA has detected that it is actually snowing on Mars, right now. The snow is forming and falling from clouds 2.5 miles high in the Martian atmosphere.
At the moment it is all melting before it reaches the ground.
But if it snows during the Martian winter, it is expected to
reach the surface, and remain as snow. Exciting

http://computerworld.com/action/article.do?command=viewArticleBasic&articleId=9115839

and from NASA

http://www.nasa.gov/news/index.html

Thats nice